Always a problem, the counterfeiting issue has exploded this year, sellers say, following Amazon’s effort to openly court Chinese manufacturers, weaving them intimately into the company’s expansive logistics operation. Merchants are perpetually unsure of who or what may kill their sales on any given day and how much time they’ll have to spend hunting down fakers.

Some of the signs of fakers include lots of reviews that say “I received this item at discount in exchange for an honest and unbiased review.” And just because an item is cheapest and/or is listed as the bestseller in the category, doesn’t make it the real deal. As always, caveat emptor.

If you want to weed out the sub-standard products, you will want to get familiar with Fakespot.com.